The Jetstream 4 is a extremely rugged air starter motor that’s ideal for harsh or dirty conditions. Its compact size also makes it ideal for applications where space is limited. The Jetstream 4 can be made even more compact by using a remote relay valve instead of the standard integrated equivalent.
Unlike pre-engaged starter motors, inertia starter motors immediately rotate the pinion upon activation. As the pinion rotates at high speed it moves forward to engage with the engine ring gear. If the pinion doesn’t engage immediately (i.e. the pinion tooth hits the ring gear rather than engages) the drive has a mechanism which allows the pinion to ‘bounce’ back to try and engage again.
The starter remains engaged with the ring gear until the engine accelerates and over speeds the starter motor. An integrated centrifugal clutch then ‘throws’ the pinion out of engagement with the ring gear.
Unlike inertia starters, a pre-engaged air starter motor only rotates the pinion at high speed after it has fully engaged with the ring-gear. There is no collision between a rapidly rotating pinion and a stationary ring-gear.
A relay valve controls the movement of the pinion, sliding it along the shaft until it connects with the ring-gear. Once engaged the full pneumatic (air) pressure is released through the starter motor to crank the engine.
ATEX regulations ensure that products are safe for use in explosive environments. IPU’s pre-engaged air starter motors conform to ATEX EN1834-1 and 2. This certifies that they are safe for use in flammable gas atmospheres as well as underground environments vulnerable to combustible dust. IPU’s air starter motors are ATEX approved because of their cast iron construction and because they use a pre-engaged starting method.